Stimulation of penis erection

ABSTRACT

A penis erection stimulation system comprises a fully implantable drug delivery device for delivering a drug in relation to a penis to achieve erection of the penis. The drug delivery device may comprise a catheter adapted to be implanted in the corpora cavernosa of a penis or in close proximity thereto in order to deliver drugs through said catheter. Alternatively, one or more infusion needles may be disposed within and implanted along with one or more housings adjacent the patient&#39;s left and right corpora cavernosa. A reservoir and a pump may also be implanted inside the patient&#39;s body to supply the infusion needle with infusion liquid. A drive unit also adapted for implantation inside the patient&#39;s body is arranged for advancing and retracting the tip end of the infusion needle such that it penetrates the housing at least in two different penetration areas either simultaneously or in immediate time succession, thereby injecting drugs along with the infusion liquid into the patient&#39;s body for stimulating penis erection.

This application is the U.S. national phase of International ApplicationNo. PCT/EP2009/007288, filed 9 Oct. 2009, which designated the U.S. andclaims the benefit of U.S. Provisional No. 61/136,878, the entirecontents of each of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to the infusion of a drug into a patient'sbody in order to stimulate penis erection.

When a male is stimulated erotically, connections between arteries andveins are closed (arteriovenous anastomoses) so that blood which isnormally able to bypass the empty spaces or sinuses of the corporacavernosa is retained in the penis.

The main vessels supplying the blood to the cavernous spaces in theerectile tissue of the corpora cavernosa are the deep arteries of thepenis. They are therefore heavily involved in the erection of the penis.They give off numerous branches—the helicine arteries—that open directlyinto the cavernous spaces. When the penis is flaccid, these arteries arecoiled, restricting blood flow. However, the smooth muscle in the coiledhelicine arteries relaxes as a result of parasympathetic stimulation. Intheir relaxed state, the helicine arteries straighten, enlarging theirlumina and allowing blood to flow into and dilate the cavernous spacesin the corpora of the penis at arterial pressure. In combination withthe bulbospongiosus and ischiocavernosus muscles compressing the veinsegressing from the corpora cavernosa, the erectile bodies of the penisbecome enlarged and rigid, and an erection occurs.

Patients suffering from erectile dysfunction can cause the penis tobecome turgid by injecting into the corpora cavernosa a medicament, suchas papaverine or prostaglandin E1, causing the smooth muscles to relax.The patients have to learn a certain technique under doctor'ssupervision in order to be able to properly inject the medicament ineach of the corpora cavernosa. Only after about 15 minutes afteradministration of the medicament will the medicament become effective.The entire procedure is inconvenient, the more so as the medicament mustusually first be mixed together from a dry substance and a salinesolution. Only as a dry substance (and typically cooled) are theavailable medicaments stable.

Furthermore, proper administration and dosing is critical since themedicament may be transported with the blood into other regions of thepatient's body if the injection is not done properly.

Recently, a different method has become known under the brand Muse®. Inthis method, a plastic rod comprising the medicament alprostadil isinserted into the urethra. Upon pressing a button, the alprostadil isreleased from the rod into the urethra. After removal of the plasticrod, the penis is rolled between the palms of the hands so that themedicament dissolves, distributes and is absorbed through the urethrawall.

It is the object of the present invention to improve the stimulation ofan erection so that the entire process is more convenient for thepatient.

SUMMARY OF THE INVENTION

The essence of the invention lies in injecting a drug into the patient'sbody so as to stimulate penis erection using a fully implantable drugdelivery device for delivering the drug in relation to the patient'spenis. This will greatly improve the patient's comfort as he no longerneeds to pierce himself with the infusion needle, which for many peopleis not an easy task. More specifically, the drug may be supplied, morespecifically injected, into both the right and left corpus cavernosumand/or the two deep arteries thereof and/or possibly muscle tissueregulating blood flow through the right and left corpus cavernosumand/or tissue in close proximity to the left and right corpuscavernosum. According to a first, most simple embodiment, the drugdelivery device comprises a catheter adapted to be implanted outside thecorpora cavernosa in close proximity thereto so as to supply the drugsthrough the catheter. Alternatively, the catheter may be adapted to beimplanted in at least one of the corpora cavernosa so as to supply thedrugs directly into the corpus cavernosum through the catheter. Thelatter alternative is more complicated to implant, but more efficient inuse.

According to a preferred, somewhat more complex embodiment, the drugdelivery device comprises at least one infusion needle for injecting thedrugs, wherein the infusion needle is permanently implanted at anappropriate location inside the patient's body. Due to the permanentimplantation of the infusion needle, the injection will always occur atthe proper location, said location being selected such that the drug ismost effective. While there are many conceivable technical variationsfor injecting the drug through the infusion needle into the patient'sbody, such injections are definitely more convenient for the patientonce the infusion needle has been implanted as compared to thealternative of injecting the drug into the penis manually from outsidethe penis. In particular, the infusion needle may be integrated in theabove-mentioned catheter.

The infusion needle of the drug delivery device may be adapted to beplaced outside the corpora cavernosa in close proximity thereto and mayfurther be adapted to change its position outside the corpora cavernosa,when the drug delivery device is implanted. Thus, whenever the needle'sposition is changed outside the corpora cavernosa, drugs are deliveredthrough the infusion needle into a region outside the corpora cavernosa.Alternatively, the at least one infusion needle being placed outside thecorpora cavernosa may be adapted to be advanced into and retracted fromthe at least one of the corpora cavernosa. In this case, whenever theneedle is advanced into the corpus cavernosum, the drugs are deliveredthrough the infusion needle into the corpus cavernosum. This latteralternative is more efficient in use.

Most preferably, one or more infusion needles are arranged at least withthe tip end or ends thereof disposed within (at least one) housing so asto penetrate the housing's outer wall or walls in at least onepenetration area, more preferably in two or more different penetrationareas. Arranging the infusion needle's tip end in a housing prevents anyfibrosis from growing into the infusion needle. Preferably, the needleor needles are fully accommodated in said housing. Where more than oneneedle is provided, the needles—or at least the tip ends thereof—may bearranged in separate housings. The housing or housings are adapted forimplantation inside the patient's body adjacent the two corporacavernosa and/or the two deep arteries thereof and/or adjacent muscletissue regulating blood flow through the patient's left and right corpuscavernosum and/or adjacent tissue in close proximity to the two corporacavernosa. Where the at least one infusion needle is arranged forpenetrating the at least one housing in two or more differentpenetration areas, the distance between the different penetration areasto be penetrated by the at least one infusion needle is selected suchthat the respective parts of the patient's body are pierced whenever thedrug is to be injected. As will be described below, two or more infusionneedles may be provided in a single housing or in different housings inorder to inject the drug in the two or more different penetration areas,or a single infusion needle may be provided in a single housing alongwith an appropriate drive unit for displacing the tip end of theinfusion needle so as to penetrate the single housing's outer wall inthe respective different penetration areas.

Furthermore, according to the invention, at least one drive unit, whichis also adapted for implantation inside the patient's body, is coupledto the at least one infusion needle so as to—at least—advance andretract the tip end of the at least one infusion needle in such a waythat it penetrates at least two of said different penetration areaswithin the housing's or housings' outer wall, so as to allow forstimulation of penis erection by injecting the substance through said atleast two different penetration areas via the at least one infusionneedle. For instance, the at least one infusion needle may be arrangedfor penetrating the at least two different penetration areas eithersimultaneously (e.g. where a plurality of needles, i.e. at least twoneedles, are provided) or in immediate time succession (e.g. where asingle needle is provided).

Preferably, a single command or single action from the patient issufficient for injecting the substance through the at least twopenetration areas, either due to a corresponding mechanical structure ofthe drive unit or due to a suitably configured control unit controllingthe drive unit. This will make the handling of the system easy for thepatient.

Where two different penetration areas are pierced in immediate timesuccession, the time delay between the penetration of the first and thesecond of the penetration areas is preferably as short as possible, morepreferably less than 120 seconds, and most preferably less than 60seconds. This can be achieved by means of a properly controlled driveunit. A longer time delay would be inconvenient for the patient.Therefore, it is preferred that, once the infusion needle has beenretracted from a first of the two penetration areas, it is immediatelyadvanced to the second of the penetration areas.

While it is possible according to one aspect of the invention toactively open the outer wall or walls of the at least one housing forallowing the infusion needle to penetrate the outer wall, it ispreferred according to another aspect of the invention to arrange theneedle so as to penetrate the outer wall by piercing through the outerwall. For that purpose, the outer wall may either comprise flaps to bepushed aside by the infusion needle as the infusion needle is advanced,or the outer wall may be made at least in the penetration areas from amaterial which is self-sealing in respect of penetrations resulting fromthe at least one infusion needle. While the entire housing may be madefrom the self-sealing material, it is advantageous for stability reasonsif the self-sealing material forms at least one window area in the outerwall, the window area being positioned for penetration by the tip end ofthe at least one infusion needle. The window area may be formed by aself-sealing penetration membrane which is preferably integrated in theouter wall by press fitting it into the outer wall.

Typically, the self-sealing material would be made from a polymermaterial which preferably comprises silicone. Other biocompatiblepolymer materials, such as polyurethane and the like, may be employed aswell.

The self-sealing material may also be a composite material. Aparticularly preferred embodiment of such composite material comprisesat least one outer shape-giving layer and a self-sealing soft materialcontained within the outer layer. Thus, the outer layer forms a shellfor the soft material. The outer layer may be made from a biocompatiblepolymer, such as one of those polymers mentioned above, and preferablythe self-sealing soft material may be a gel.

Instead of a self-sealing material, the part of the outer wall to bepenetrated by the infusion needle may comprise one or more flaps in thepenetration areas through which the infusion needle or needles can pass.This can reduce the force needed for the infusion needle to penetratethe outer wall, as compared to the penetration of a self-sealingmembrane. The flap is preferably arranged to be pushed aside by theinfusion needle upon advancement of the infusion needle.

Alternatively, the outer wall may comprise at least one door in thepenetration areas. A drive is connected to the door for actively openingthe door so as to allow for the infusion needle to be advanced throughthe opened door. Again, the door may comprise a flap, such as aresilient, normally closed flap. It is particularly preferred if thedrive connected to the door forms part of the drive unit coupled to theinfusion needle. More specifically, the arrangement may be such thatadvancement of the infusion needle by means of the drive unitsimultaneously causes the drive to open the door.

Where a single housing is provided for the at least one infusion needle(or at least for the tip ends thereof) or where two or more penetrationareas are arranged in a single housing, the penetration areas may bearranged in the housing so that they can be placed either adjacent toboth the right and left corpus cavernosum of the patient's penis and/orthe two deep arteries of the right and left corpus cavernosum and/oradjacent to muscle tissue regulating blood flow through the right andleft corpus cavernosum and/or in sufficiently close proximity to anothertype of tissue allowing both the first and second corpus cavernosum tobecome turgid when the particular drug is injected thereinto.

The at least one infusion needle preferably has a tube-like body closedat the tip end and provided with a laterally arranged delivery exit portfor delivery of the drug into the particular body part. Therefore, theneedle will not cut out any material but will simply divide it duringpenetration. Thus, when the needle penetrates any material, such asfibrosis and/or the self-sealing penetration membrane, there will be nomaterial entering and blocking the drug delivery passageway.

As mentioned above, a separate infusion needle may be provided for eachof the two or more penetration areas. Thus, where injection is desiredto occur in only two different areas to provoke penis erection, twoseparate infusion needles may be advanced through the correspondingpenetration area of the respective housing—preferably simultaneously—andretracted again after injection.

According to a preferred embodiment of the invention, a plurality of twoor more infusion needles are provided for each of the differentpenetration areas and arranged for penetrating different penetrationsites within each of said different penetration areas. This allows forpenetrating different sites within each penetration area at differenttimes, thereby giving the human tissue time to recover from the piercingby the infusion needle. This can be achieved with a drive unit suitablyconfigured to advance and retract one infusion needle in each of saiddifferent penetration areas at one time, and to advance and retract adifferent infusion needle in each of said different penetration areas ata different time.

The system may further comprise at least one reservoir adapted forimplantation inside the patient's body, the reservoir being in fluidconnection with the at least one infusion needle so as to supply to theinfusion needle the substance to be injected into the patient's body.Also, at least one pump, which is also adapted for implantation insidethe patient's body, may be provided to advance the substance from thereservoir to the at least one infusion needle.

Since it is preferred for reasons of space constraints to implant thereservoir remote from the injection areas, it can be advantageous toemploy long infusion needles that are flexibly bendable. The tip ends ofsuch infusion needles would then be arranged within at least one firsthousing so as to penetrate the outer wall thereof upon advancement ofthe long infusion needle. The at least one first housing accommodatingthe tip end of such long infusion needle or needles can be arranged inclose proximity to the injection area so that the tip end can penetratethe outer wall of the first housing upon advancement of the longinfusion needle. The respective other end of the infusion needle orneedles, i.e. the infusion needle's rear end, is arranged in at leastone second housing which can be implanted inside the patient's bodyremote from the first housing in an area with less space constraints.The injection needle would be sufficiently long to bridge the distancefrom the second housing for remote implantation to the first housing andfurther through the first housing up to the outer wall of the firsthousing to be penetrated by the needle. The long and flexibly bendableinfusion needle may be guided within a suitable sheath. Since the rearend of the long infusion needle or needles is remotely implanted withinthe patient's body, other components of the system cooperating with rearend of the long infusion needle may also be implanted remote from theinjection area, such as the reservoir for storing the substance to beinjected, the pump for advancing the drug from the reservoir to theinfusion needle and further through the needle into the patient's body,and a motor for actuating the system's active parts. In a particularlypreferred embodiment, the tip end of the long infusion needle isadvanced by advancing the entire needle from the infusion needle's rearend. In this context, it is particularly advantageous to also arrange atleast a part of the drive unit, preferably the entire drive unit, foradvancing and retracting the tip end of the infusion needle remote fromthe injection area, preferably within the second housing and even morepreferably in a common housing with the remotely implanted reservoir.More preferably, most or all of the active parts, such as a motor, pumpand the like, may be accommodated in the remotely implanted secondhousing, whereas the first housing only includes passive elements.

A drive unit according to the present invention includes not only thedrive itself, such as an electric motor, but also those components whichare involved in transforming the driving energy provided by the driveinto movement of the at least one needle, such as transmission gears andthe like.

For instance, in the case of the long flexibly bendable infusion needle,the drive unit may be such that the infusion needle is advanced and/orretracted by turning the infusion needle or by turning an elementcooperating with the infusion needle. More specifically, the drive unitfor advancing and retracting the infusion needle may comprise a screwdrive connection. For instance, the drive of the drive unit may turn ascrew threadingly engaged with a rack coupled to the infusion needle sothat rotation of the screw will cause the infusion needle to be advancedor retracted. The screw and rack of the screw drive connection arepreferably accommodated in the remotely implanted second housing but mayalso be arranged in the housing accommodating the tip end of the needle.Instead of the screw, the infusion needle itself may be rotated by meansof a suitable drive so that threading on the needle engaging a fixedlymounted rack causes the infusion needle to advance or retract uponrotation of the infusion needle. Between the first and second housings,the infusion needle is preferably guided in a sheath, so as to reducefriction and prevent growth of fibrosis that might hinder movement ofthe needle.

According to a particularly preferred aspect of the invention, the tipend or ends of the at least one infusion needle are laterally movable,so as to vary the penetration sites within a particular penetration areaof the at least one housing's outer wall, thereby varying the injectionsite within the particular injection area in the patient's body. As setout above, frequent piercing of the same body part may cause irritation,eventually making further piercing difficult or even impossible.Variation of the injection site by laterally displacing the needle uponeach injection cycle may overcome such problems. Accordingly, the atleast one drive unit in the common housing is preferably configured tolaterally displace the tip end or ends of the at least one infusionneedle to different penetration sites within a penetration area. Morespecifically, where two or more infusion needles are provided forpenetrating two or more different penetration areas, the drive unit ispreferably configured to laterally displace the tip ends of the infusionneedles simultaneously. This can be achieved e.g. by jointly mountingthe tip ends of the infusion needles on a movable carriage of the driveunit, such as a turntable and/or a shuttle, possibly in the form of aslide. Thus, the drive unit for advancing and retracting the tip end orends of the at least one infusion needle is preferably configured so asto also laterally displace a tip end each time the tip end is advancedor retracted.

Thus, the lateral displacement and the advancement/retraction of the tipend of an infusion needle is coordinated. The lateral displacement ofthe tip end of the infusion needle may take place before and/or after aninjection. The mechanism may be such that after a certain number oflateral displacements or after lateral displacement over a predefineddistance, the tip end of the infusion needle is laterally returned toits initial position so that the next number of infusions will takeplace again at locations that have previously been penetrated by theneedle. It is even preferred to configure the drive unit such that thetip end of the infusion needle is displaced in at least two differentlateral directions within one penetration area. For instance, when theinfusion needle has laterally returned to its initial position, the nextnumber of infusions may take place somewhat laterally offset above orbelow the first number of penetration sites. This permits atwo-dimensional array of penetration sites to be obtained. Inparticular, the drive unit may be configured to displace the tip end ofthe infusion needle along a curved path, which will result in athree-dimensional array of penetration sites if the needle isdisplaceable in different lateral directions.

Where two or more infusion needles are provided for penetrating two ormore different penetration areas, the infusion needles or, in the caseof the aforementioned long and flexibly bendable infusion needles, atleast the tip ends thereof may be contained in a common housing inspaced apart relationship, with the drive unit being configured toadvance and retract the tip ends of the infusion needles so as topenetrate the outer wall of the common housing in said at least twodifferent penetration areas, again preferably simultaneously. Theinfusion needles—or at least the tip ends thereof—may be arranged oneabove the other within the common housing. Generally speaking, it ispreferable in such a situation that the direction of lateraldisplacement of the tip ends of the infusion needle within differentpenetration areas is different from, in particular perpendicular to, thedirection of distance between the different penetration areas.Alternatively, where the infusion needles are arranged with greatlateral distance between each other, the direction of lateraldisplacement of the tip ends of the infusion needles within each of twodifferent penetration areas may generally be the same as the directionof distance between the two different penetration areas. Placing the twoor more injection needles—or at least the tip ends thereof—in a commonhousing simplifies the procedure of fixing the needles in place close tothe injection areas. Furthermore, a single drive unit may be used foradvancing and retracting the tip ends of the plurality of infusionneedles, this making the entire system less voluminous. The use of asingle drive unit is particularly advantageous where a major part of thedrive unit is also contained in the common housing, i.e. where a majorpart of the drive unit is also to be implanted close to the veryconstrained injection area.

Instead of providing two or more infusion needles for penetrating two ormore different penetration areas, it is likewise possible to provide asingle infusion needle or the tip end of a single needle within thehousing and to implant the housing within the patient's body adjacentthe two or more injection areas. In this case, the drive unit may beconfigured so as to laterally displace the tip end of the single oneinfusion needle between various lateral positions such that the infusionneedle can penetrate the housing's outer wall in the differentpenetration areas. The distance of lateral displacement of the singleinfusion needle between the different penetration areas would amount to3 mm, 4 mm, 5 mm or even more upon each successive injection. Suchsuccessive injections are preferably in immediate time succession,preferably not exceeding 120 seconds between two injections, morepreferably not exceeding 60 seconds. Most preferably, the drive unitwill be adapted to initiate advancement of the one infusion needle to asecond one of the plurality of penetration areas once it has beenretracted from a first one of the penetration areas.

An implantable infusion device comprising a single, laterallydisplaceable infusion needle contained within a housing so as topenetrate the housing's outer wall at different penetration sites isgenerally known from WO 2007/051563. However, this prior art infusiondevice is not aimed at being used for the stimulation of penis erection.Also the prior art device is neither intended nor configured forinjecting drugs simultaneously or quasi-simultaneously in immediate timesuccession in two or more different injection areas. The drive unit ofthe prior art device is instead configured to administer the drug at adifferent penetration site of a single injection area at each time ofoperation. For instance, the prior art device may be placed along ablood vessel so as to inject drugs at different injection sites within asingle injection area of the blood vessel. Thus, the distance of lateraldisplacement of the tip end of the infusion needle between one injectionand a next following injection is not configured in the prior art devicesuch that different injection areas within the patient's body could bereached.

Turning back to the present invention, it is again preferable, when thepatient desires to achieve another penis erection at a later point oftime, that the single infusion needle does not penetrate the samepenetration site within the particular penetration area of the housing'souter wall, but that the drive unit is configured to laterally displacethe tip end of the one infusion needle to different penetration siteswithin each of the different penetration areas. Again, the direction oflateral displacement of the tip end of the one infusion needle withineach of the different penetration areas may either be the same as thedirection of lateral displacement of the tip end of the infusion needlebetween the different penetration areas, or may be different from, inparticular perpendicular to, the direction of lateral displacement ofthe tip end of the infusion needle between the different penetrationareas. Depending upon the particular configuration of the system, thismay be achieved with a single, multifunctional drive unit or with aplurality of different drive units suitably arranged to work incoordinated fashion. Even a combination of these alternatives ispossible. For instance, when after a number of infusion cycles thesingle infusion needle has laterally returned to its initial position,the next number of infusions within the same penetration area may takeplace somewhat laterally offset above or below the first number ofpenetration sites. Thus, a two-dimensional array of penetration sitescan be obtained in each penetration area, thereby keeping the maximumdimensions of the penetration areas at a minimum.

Where the housing or at least the window area thereof is formedspherically, even a three-dimensional array of penetration sites throughthe housing's outer wall can be obtained by means of a suitably adapteddrive unit for the needle displacement. This greatly increases thesystem's flexibility of use.

Regardless of the number of needles involved and regardless of theparticular penetration site array to be achieved, it is preferable toconfigure the drive unit such that the lateral displacement of the tipend of the infusion needle or needles is achieved automatically duringadvancement and/or retraction of the tip end of the needle or needles.For instance, where the infusion needle is mounted on a movable carriagefor the lateral displacement of the tip end of the needle, such as on aturntable or a shuttle, e.g. in the form of a slide, the drive unit maycomprise a stepper which is adapted to automatically advance the movablecarriage a predefined distance upon each advancement and/or retractionof the infusion needle.

Now, turning to the reservoir, it should be considered that long termstorage is not possible with many currently available drugs, this beingparticularly true of drugs stimulating penis erection. Where long termstorage is desired, the drug to be injected would typically be providedas a first substance and mixed with a second substance for injectionshortly before the injection is performed. Therefore, according to apreferred embodiment of the present invention, the reservoir of thesystem comprises at least one first compartment, e.g. for accommodatingan infusion liquid such as a saline solution, and at least one secondcompartment, e.g. containing a drug, in particular a drug in dry form,for mixing with the infusion liquid of the first compartment. The drugmay be in powder form and, more specifically, may be a freeze-drieddrug. In particular, the drug contained in the second compartment wouldbe a drug for stimulating penis erection. A mixing chamber may beprovided for mixing the substance from the first compartment with thesubstance from one or more of the at least one second compartment.

The number of the second compartments may be huge, such as 50 or more,in particular 100 or more. This would not constitute a particularproblem in terms of space constraints since the amount of drugs requiredfor each stimulation of penis erection is extremely little and wouldamount to a few micrograms. Furthermore, the reservoir may be adaptedfor implantation within the patient's body remote from the housingcontaining the needle, such as close to the symphyseal bone. There is alot of space available above the patient's symphyseal bone, and thedrugs could be delivered to the tip end of the needle through anappropriate conduit. If desired, one can inject pure saline solutionafter the drug injection has been completed so as to clean the conduitand needle from any drug residue. Such cleaning injection could be donethrough a different penetration area of the housing's outer wall intotissue of the patient which would not affect penis stimulation.

Preferably, the second compartments containing the drug areliquid-tightly sealed against the first compartment, with a mechanismbeing provided for individually opening a connection between the secondcompartments and the first compartment.

According to a preferred embodiment, the second compartments are mountedin a plate so as to open towards a first side of the plate and theopening mechanism is adapted to act on the second compartments from asecond side of the plate opposite the first side of the plate so thatthe compartments open to the first side of the plate. Thus, the secondcompartments may be pushed from their rear side (second side of theplate) so as to open frontward into e.g. a mixing chamber in which thecontent of the opened second compartments mixes with the content of thefirst compartment of the reservoir, such as with saline solution. Morespecifically, the second compartments may be mounted in the plate asdisplaceable drug containers and the opening mechanism may be adapted todisplace the drug containers such that they deliver their drug contentsin the manner described.

Alternatively, the plate may be rotatable so as to allow the drugcontainers to be brought into alignment with a conduit upon rotation ofthe plate. Thus, when the drug is brought into alignment with suchconduit, it may be mixed with e.g. saline solution pumped through theconduit towards the infusion needle.

According to another preferred embodiment, the second compartments aremounted on a tape wound up on a reel. A plurality of rows of the secondcompartments may be arranged on the tape in side-by-side relationship ina direction different to the winding direction of the tape. This way,the length of the tape can be reduced. It is particularly preferable ifthe tape is contained in a replaceable cassette. Thus, when all of thesecond compartments of the tape are emptied, the tape can be easilyreplaced by replacing the cassette.

As mentioned above, while the reservoir may generally be part of thehousing accommodating the at least one infusion needle, it is preferredto arrange the reservoir separate from the housing for remoteimplantation within the patient's body.

At least a section of a periphery of the first compartment of thereservoir may be made from a flexible material permitting volume changesof the first compartment by deformation of the flexible material asinfusion liquid is filled into or drawn out of the reservoir. Thus, thereservoir may be of balloon type. The flexible material may comprise apolymer membrane. A bellows construction is preferable having pre-bentcreases to reduce long term degradation.

According to a particular embodiment, drawing liquid from the reservoirmay cause a pressure decrease in at least part of the reservoir so thata negative pressure is attained as compared to the pressure in front ofthe infusion needle. For instance, the first compartment of thereservoir may comprise a gas chamber and a liquid chamber, said chambersbeing separated by a membrane, e.g. the polymer membrane. When liquid isdrawn from the liquid chamber, the pressure in the gas chamber willdecrease accordingly.

The reservoir may have an injection port for injecting liquid fromoutside the human body into the implanted reservoir. That way, thereservoir implanted in the patient's body along with the drug deliverydevice may be kept relatively small since the reservoir can be refilledeasily at appropriate time intervals, possibly with a doctor's aid.

Preferably, the injection port comprises a self-sealing material inrespect of penetrations caused by a replenishing syringe that would betypically used to refill the reservoir through the patient's skin. It ispreferable to implant the self-sealing injection port of the reservoirsubcutaneously in the patient's body so that it is easily accessible forrefill by means of the syringe.

The conduit or conduits for connecting the remotely implanted reservoirwith the infusion needle or needles should have a length sufficient tobridge the distance between the patient's symphyseal bone and theinferior fascia of the patient's urogenital diaphragm, where the housingis preferably to be placed. Accordingly, the conduit should have alength of 10 cm or more.

While it has already been pointed out that drugs, in particular thedrugs for stimulating penis erection, may degrade upon long termstorage, another important influence on drug degradation is the storagetemperature. Some drugs have to be stored in a refrigerator at low or atleast moderate temperature. A preferred embodiment of the inventiontherefore provides for a cooling device for keeping the content withinat least one compartment of the reservoir at a temperature below 37° C.This can be achieved with relatively little energy supply if the amountof drugs to be cooled is extremely little, as explained above, and iffurthermore the drug compartment within the reservoir is thermallyinsulated. For instance, the reservoir may be comprised in an insulationchamber.

It is preferred to provide the cooling device with a heat exchanger forexchanging with the patient's body heat generated by the cooling device.Such heat exchanger may be implanted within the patient's body remotefrom the cooling device to safely dissipate the heat energy in an areawhere it cannot adversely affect the content of the reservoir.

The cooling device can be of a variety of different types. According toa first embodiment, the cooling device may contain at least twodifferent chemicals reacting with each other, thereby consuming thermalenergy which energy is drawn from the contents within the reservoir sothat a cooling effect on the contents is achieved. The two chemicals maybe provided in separate chambers and a flow control device may beprovided to bring together certain amounts of the two differentchemicals so as to control the amount of thermal energy drawn from thecontents within the reservoir.

According to a second embodiment, the cooling device may comprise atleast one Peltier element. A Peltier element is an electrothermalconverter causing a temperature difference to occur when an electriccurrent is flowing through the element, based on the Peltier effect.While one part of the Peltier element cools down, a different partthereof heats up. Such heat may again be removed by means of a heatexchanger or simply by providing the particular part generating the heatwith an enlarged surface so that the heat is directly dissipated intothe adjacent body part of the patient.

According to a third embodiment, the cooling device may be of arefrigerator-type construction. That is, heat exchanging pipes within achamber to be cooled and heat exchanging pipes outside the chamber fordissipating the heat energy absorbed in the cooling chamber are providedalong with a compressor for compressing the refrigerant gas when itexits the cooling chamber and an expansion valve for expanding therefrigerant gas before it re-enters the cooling chamber.

Turning now to the pump for advancing the infusion liquid from thereservoir to the infusion needle or needles, such pump may be a manuallydriven pump or an automatically driven pump. The manually driven pumpmay be formed from a balloon which may be manually compressed ifsuitably arranged under the patient's skin. The balloon type pump may atthe same time serve as a reservoir for the infusion liquid, inparticular for the saline solution. Preferably, however, anautomatically driven pump is used. While the type of pump is notcritical, one specific type of pump is particularly preferred. Moreparticularly, an implantable pump preferably comprises a valve devicehaving a first and a second valve member, each having a smooth surfacefacing each other so as to form a sealing contact between the first andsecond valve members and further having different liquid channels thatcan be brought into alignment by displacement of the two smooth surfacesrelative to one another while maintaining the sealing contact. This typeof pump is described in great detail in WO 2004/012806 A1. The first andsecond valve members are preferably made from a ceramic material for itsexcellent sealing capabilities over a long period of time and itsinertness to many substances.

The pump may be a membrane type pump, as also described in WO2004/012806 A1, but is not restricted to this type of pump. The membranetype pump may comprise a membrane displaceable by a piston as the pistonmoves, the piston being coupled to the valve device so as to slidablydisplace the first and second valve members relative to one another asthe piston moves. Preferably, the pump will be implanted separate fromthe housing accommodating the needle or needles for remote implantationwithin the patient's body.

Due to the space constraints within the patient's body in the area whereinjection is to take place, it is advantageous to implant as manycomponents of the system as possible remote from the housingaccommodating the infusion needle or needles. In this context, the driveunit may comprise a mechanical drive element for transmitting kineticenergy from a remote location within the patient's body to the at leastone infusion needle. The mechanical drive element may comprise arotating shaft by which a considerable distance can be bridged withinthe patient's body. The rotating shaft may, upon rotation about its axisof rotation, cause movement of the infusion needle either directly orindirectly. More specifically, the rotating shaft may be in the form ofa worm screw which, when turned, causes the infusion needle or needlesto advance and retract and/or causes the infusion needle or needles tomove laterally upon each advancement/retraction. Individual rotatingshafts or worm screws may be provided for each individual infusionneedle and/or for advancing and retracting the tip end of the infusionneedle or needles on the one hand and laterally displacing the tip endof the infusion needle or needles on the other hand. Most preferably,the rotating shaft or worm screw is flexibly bendable, so that it can befreely arranged within the patient's body.

Alternatively or in addition, the drive unit may comprise at least onewire directly or indirectly cooperating with the infusion needle so asto cause movement of the infusion needle upon actuation of the wire.Thus, the wire may be pulled at one end thereof which is located withinthe patient's body remote from the injection sites. Preferably, the wireextends through the same conduit which connects the infusion needle orneedles with the reservoir. More specifically, pulling the wire maycause the tip end of the infusion needle or needles to displacelaterally from a first to a second of the different penetration areas orfrom a first penetration site to a second penetration site within asingle one of the different penetration areas. A single pulling wire maybe sufficient to cause movement of the infusion needle in one direction,whereas a spring element or any other pretensioning means may beprovided to urge the infusion needle back to the initial startingposition or to a different starting position. Alternatively, two pullingwires may be provided to move the infusion needle back and forth in asingle dimension.

According to a preferred embodiment, the infusion needle is arranged fortwo-dimensional lateral displacement. This can be achieved by means oftwo pulling wires, preferably cooperating again with spring elements orother pretensioning means to provide a counterforce to be overcome bypulling the wires. Alternatively, three pulling wires may be provided tolaterally displace the tip end of the infusion needle back and forthalong at least two directions within a two-dimensional plane.

A pulling wire may also be arranged to advance or retract the infusionneedle by pulling the wire. Again, a spring element or otherpretensioning means may be provided to urge the infusion needle back toits initial starting position or to a different starting position.

Alternatively, the drive unit may comprise a hydraulic drive fortransmitting hydraulic energy from a remote location within thepatient's body to the at least one infusion needle for advancing the tipend thereof and/or for laterally displacing the tip end thereof. Theinfusion liquid itself may be used as the hydraulic medium providing thehydraulic energy, or a secondary liquid different from the infusionliquid may be used.

Further alternatively, the drive unit may comprise one or more electricmotors inside the housing accommodating the at least one infusionneedle. In this case, energy may be transmitted from a remote locationwithin the patient's body to the at least one motor by means ofappropriate wiring. Again, as in the two afore-described alternatives, asingle motor may be provided for advancing and retracting the tip end ofthe infusion needle or needles and for laterally displacing the tip endof the infusion needle or needles, or individual motors may be providedfor each individual infusion needle and/or for advancing the tip ends ofthe infusion needle or needles on the one hand and laterally displacingthe infusion needle or needles on the other hand.

Even further alternatively, the drive unit may comprise anelectromagnetic drive for laterally displacing and/or for advancing andretracting the tip end of the infusion needle or needles. For instance,the electromagnetic drive may comprise a group of electromagnetscomposed of a plurality of laterally spaced apart electromagnet firstparts and at least one electromagnet second part, the electromagnetsecond part cooperating with an energized one of the electromagnet firstparts. The electromagnet second part is fixedly connected to theinfusion needle or needles either directly or indirectly so that uponenergization of one or more of the electromagnet first parts theelectromagnet second part and, thus, the infusion needle or needles willbe caused to move. The arrangement of the electromagnet first parts andsecond part may be such that the electromagnet first parts are arrangedin a first plane and the electromagnet second part is movable in frontof or behind the first plane. Alternatively, the electromagnet firstparts may face each other, thereby defining a first plane between them,and the electromagnet second part may be movable within the first plane.Depending on which one or ones of the electromagnet first parts areenergized, the electromagnet second part with the infusion needle orneedles fixed thereto will move accordingly. The electromagnet firstparts preferably each include a magnetic coil.

In either one of the aforementioned alternatives, it is advantageous totransmit the driving energy through the conduit that connects the atleast one infusion needle with the remotely implanted reservoir. Thatis, in the case of a mechanical drive element in the form of a wire orrotating shaft, the wire/shaft and the infusion liquid may be guidedthrough a common conduit. The common conduit may comprise two separatepaths, one for the shaft or wire and one for the infusion liquid. Such acommon conduit facilitates the handling and arrangement of the systemduring implantation. Similarly, the wiring for transmitting electricenergy to the motor or to the electromagnetic drive may be guidedthrough a conduit connecting the infusion needle or needles with thereservoir.

Where the pump and/or drive unit is not actuated manually, a drive inthe form of a motor may be arranged e.g. for electrically, magneticallyor electromagnetically actuating the pump and/or drive unit or forhydraulically actuating the pump and/or drive unit. The motor ispreferably arranged for actuating either the pump or the drive unit,thereby causing simultaneous actuation of the other, e.g. the drive unitor the pump. A motor may also be provided for actuation of any otherenergy consuming part of the drug delivery device. More specifically, aplurality of motors may be provided, e.g. an individual motor for eachinfusion needle and/or an individual motor for displacing the tip end ofthe infusion needle in a lateral direction on the one hand and foradvancing the tip end of the infusion needle through the housing's outerwall on the other hand.

Again, for reasons of space constraints in the area of implantation ofthe housing accommodating the infusion needle or needles, it isadvantageous to remotely implant the motor within the patient's bodyseparate from the housing. Again, actuating means may be provided formanual activation of the motor or motors, such actuating meanspreferably being adapted for subcutaneous implantation.

The term “motor” according to the present invention includes anythingthat employs energy other than manual power and either automaticallytransforms such energy into kinetic or hydraulic or another type ofenergy or directly uses such energy to activate the pump, drive unitand/or other part of the overall system. As such, it is possible thatpart of the drive unit also forms part of the motor, e.g. in the case ofan electromagnetically actuated drive unit.

Coupling elements may be provided either for conductive or for wirelessenergy transfer from outside the patient's body to the motor. Forinstance, the motor may be arranged for being wirelessly driven by anexternal electromagnetic field.

An energy source for providing energy to at least one of the pump, thedrive unit and the drive (motor) for driving the drive unit, and anyother energy consuming part of the system may be provided. For instance,an external energy source for use outside the patient's body, such as aprimary energy source or a battery, in particular a rechargeablebattery, that may be mounted on the patient's skin, may be used toprovide energy to the pump and/or drive unit and/or any other energyconsuming part of the system. The energy source may in particular beconnected to the at least one motor for actuating these components. Anexternal energy source for wireless energy transfer may be adapted tocreate an external field, such as an electromagnetic field, magneticfield or electrical field, or create a wave signal, such as anelectromagnetic wave or sound wave signal.

Where the energy is wirelessly transferred to the implanted components,a transforming device for transforming the wirelessly transferred energyinto electric energy may be provided. Such transforming device ispreferably adapted to be placed directly under the patient's skin so asto minimize the distance and the amount of tissue between thetransforming device and the energy supply means outside the patient'sbody.

Instead of or in addition to an external energy source, the system maycomprise an internal power supply for implantation within a patient'sbody. While such implantable power supply may be part of or may becontained within the housing accommodating the infusion needle orneedles, it is preferred to provide the implantable energy sourceseparate from the housing for remote implantation within the patient'sbody. Such implantable power supply preferably comprises energy storagemeans for long term storage of energy, such as a long-life battery or,more preferably, an accumulator. The accumulator has the advantage ofbeing rechargeable. Preferably, the accumulator comprises a rechargeablebattery and/or a capacitor.

Again, coupling elements for conductive or wireless energy transfer froman external power supply outside the patient's body to the accumulatormay be provided for charging the accumulator from outside the patient'sbody when the device is implanted in the patient's body. Similarly, theaccumulator may comprise coupling elements for conductive and/orwireless energy supply to the at least one motor of the drug deliverydevice.

A feedback subsystem, which may be part of a control unit describedbelow, can advantageously be provided to send feedback informationrelating to the energy to be stored in the energy storage means frominside the human body to the outside thereof. The feedback informationsignal may be sent wirelessly. The feedback information is used foradjusting the amount of energy supply, in particular the amount ofwireless energy transmitted by the energy transmitter. The feedbackinformation preferably includes information on a parameter related tothe charging process for controlling the charging process. It mayspecifically relate to an energy balance which is defined as the balancebetween an amount of wireless energy received inside the human body andan amount of energy consumed by the at least one energy consuming part.Alternatively, the parameter may relate to an energy balance which isdefined as the balance between a rate of wireless energy received insidethe human body and a rate of energy consumed by the at least one energyconsuming part. The consumed energy preferably includes the energy thatis consumed by the process of charging the implantable power supply.

Preferably, a control unit is provided for controlling an amount ofinfusion liquid to be administered through the at least one injectionneedle. A single command from the patient to the control unit, such as asingle actuation of a press button or other type of switch, issufficient for causing the control unit to control the injection of thedrugs at two different locations within the patient's body. The controlunit may be provided for controlling at least one of the pump, the driveunit and the motor and any other energy consuming part of the systemand, where the system includes an internal or external energy source,said energy source. Again, the control unit is preferably separate fromthe housing accommodating the infusion needle or needles so as to beimplantable within the patient's body. The control unit may be adjustedsuch that the appropriate amount of drugs will be administered at theappropriate time to the particular one of the injection sites. Automaticadministration will substantially relieve the patient.

Preferably, the control unit has a data transfer port for data transferbetween an external data processing device outside the patient's bodyand the control unit implanted in the patient's body, regardless ofwhether the control unit is contained in the housing accommodating theinfusion needle or needles or whether it is implanted within thepatient's body remote from said housing. The data transfer port allowsfor monitoring the control unit to adapt the system to changing needs ofthe patient. Preferably, the data transfer port is a wireless transferport for the data transfer, so as to provide easy data exchange betweenthe control unit and the external data processing device, e.g. during avisit to the doctor. Most preferably, the control unit is programmableto further increase its adaption flexibility. Instead of or in additionto the external data processing device, the control unit may comprise anexternal component for manual operation by the patient for setting intooperation the control unit.

Apart from or as a part of the control unit, feedback may be provided onparameters relevant for the treatment. Such parameters may be eitherphysical parameters of the patient and/or process parameters of thesystem. For this purpose, at least one feedback sensor is provided fordetecting such parameters. For instance, the feedback sensor may beadapted to detect one or more parameters relating to any of thefollowing: drug level, flow volume in blood vessel, pressure, electricalparameters, distension, distance, etc.

The feedback sensors may be connected to the control unit and thecontrol unit may comprise a control program for controlling drugdelivery in response to one or more signals from the feedback sensors.In addition or alternatively, feedback data may be transferred from thecontrol unit to the external data processing device. Such feedback datamay be useful for the doctor's diagnosis.

The penetration areas of the wall or walls of the housing or housingswithin which the infusion needle or needles are disposed may be arrangedin the patient's body at various locations. For instance, they may bearranged adjacent the left and right corpora cavernosa and/or the twodeep arteries running through the left and right corpora cavernosaand/or muscle tissue regulating blood flow through the patient's leftand right corpora cavernosa and/or another kind of tissue in closeproximity to the left and right corpora cavernosa.

A holder may be used to secure the corpora cavernosa to the housing orhousings so that the housing rests in place.

Other components of the system are preferably remotely implanted, suchas adjacent the patient's symphyseal bone. As discussed above, somecomponents of the system may be implanted subcutaneously. Subcutaneousimplantation increases the possibilities of wireless energy and/or datatransfer between the implanted and the extracorporal parts of thesystem. Also, refilling the reservoir through an injection port by meansof a replenishing needle penetrating through the patient's skin issubstantially facilitated when an injection port of the reservoir isimplanted subcutaneously. In particular, the compartment of thereservoir containing the saline solution might need to be refilledfrequently, whereas the other compartments comprising individual smalldoses of the drug would need no refill. It should be understood,however, that depending upon the circumstances any implantable componentof the system may be placed in the abdomen or even in the thorax.Activating means for direct manual operation by the patient may also beprovided to be implanted subcutaneously, e.g. for setting into operationone or more of the aforementioned motors or for simply setting intooperation the control unit of the system. Such activating means may bein the form of a subcutaneously implantable switch manually operable bythe patient from outside the patient's body.

The various aforementioned features of the invention may be combined inany way if such combination is not clearly contradictory. The inventionwill now be described in more detail in respect of preferred embodimentsand with reference to the accompanying drawings. Again, individualfeatures of the various embodiments may be combined or exchanged unlesssuch combination or exchange is clearly contradictory to the overallfunction of the device. In particular, while most of the embodimentsdescribed hereinafter relate to systems having one or more infusionneedles entirely accommodated within one or more housings, it islikewise possible in all of these embodiments to employ long, flexiblybendable needles having only the front ends thereof accommodated in saidhousing or housings and having the respective rear ends disposed in oneor more second housings remotely implanted within the patient's body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the muscles of the perineum,

FIG. 2 shows a cross-section through the penis,

FIG. 3 shows a top view of a first embodiment of the invention includinga single needle,

FIG. 4 shows a top view of a second embodiment of the inventionincluding a single needle and a motor accommodated in a common housing,

FIG. 5 shows a top view of a third embodiment of the invention includingtwo needles in a common housing,

FIG. 6 shows a plan view of a part of the drug delivery device of FIGS.4 and 5,

FIG. 7 shows a cross-sectional view of a penetration membrane made froma composite material,

FIG. 8 shows a cross-sectional view through the outer wall with flaps inthe penetration area,

FIG. 9 shows a cross-sectional view through the outer wall with anactively openable door in the penetration area,

FIG. 10 shows a cross-sectional view through the outer wall with anactively openable door according to another embodiment,

FIG. 11 shows a fourth embodiment including a plurality of needleswithin a common housing,

FIG. 12 shows a side view of a fifth embodiment of the inventioncomprising a single needle which is laterally and verticallydisplaceable,

FIG. 13 shows a side view of a sixth embodiment of the invention similarto the fifth embodiment, but with more steps for laterally displacingthe needle,

FIG. 14 shows a seventh, spherical embodiment of the invention forobtaining a three-dimensional array of penetration sites,

FIG. 15 shows a side view of an eighth embodiment of the inventioncomprising two needles in a common housing which are laterally andvertically displaceable,

FIG. 16 shows a side view of a ninth embodiment of the inventioncomprising two needles similar to the eighth embodiment, but with moresteps for laterally displacing the needle,

FIG. 17 shows a tenth embodiment with a principle of advancing andretracting an infusion needle by means of a pull wire,

FIG. 18 shows an eleventh embodiment with a principle of laterallydisplacing an infusion needle by means of pull wires,

FIG. 19 shows a twelfth embodiment with a principle of advancing andretracting a needle and laterally displacing a needle by means ofrotating shafts,

FIG. 20 shows the overall system of the invention implanted in apatient's body according to a first variation,

FIG. 21 shows the overall system of the invention implanted in thepatient's body according to a second variation,

FIG. 22 shows the overall system of the invention implanted in thepatient's body according to a third variation,

FIG. 23 shows drug compartments as part of the reservoir of the systemaccording to a first principle,

FIG. 24 shows drug compartments mounted on a tape wound on a reel in areplaceable cassette as part of the reservoir of the system according toa second principle,

FIG. 25 shows a part of the tape of FIG. 20 in greater detail,

FIG. 26 shows the principle of operation of the replaceable cassette ofFIG. 24,

FIG. 27 shows drug compartments as part of the reservoir of the systemaccording to a third principle,

FIG. 28 shows a cross-sectional view of the drug compartments of FIG. 27including an insulation chamber and cooling device,

FIG. 29 shows the principle of the cooling device of FIG. 28 incombination with a heat exchanger,

FIG. 30 shows a specific embodiment for the cooling device of FIG. 28,

FIG. 31 shows a part of the system implanted in the patient's bodycomprising separate needles for the right and the left corpuscavernosum,

FIG. 32 diagrammatically shows the system of FIG. 31,

FIG. 33 diagrammatically shows the system of FIG. 30 with a long,flexibly bendable infusion needle,

FIG. 34 shows a part of the system of FIGS. 32 and 33, respectively,including a tube into which the needle can be advanced,

FIGS. 35A to 35C show a first and second embodiment forelectromagnetically displacing the infusion needle in a plurality oflateral directions,

FIGS. 36A and 36B show a third embodiment for electromagneticallydisplacing the infusion needle in a plurality of lateral directions,

FIG. 37 shows the overall system of the invention implanted in apatient's body according to a fourth variation,

FIG. 38 shows the overall system of the invention implanted in thepatient's body according to a fifth variation, and

FIG. 39 shows the overall system of the invention implanted in thepatient's body according to a sixth variation.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the muscles of the perineum of a male. Reference numerals1, 2 and 3 designate the ischiocavernosus muscles, bulbospongiosusmuscles and superficial transverse perineal muscles, respectively. Thebulbospongiosus muscle surrounds lateral aspects of the bulb of thepenis at the most proximal part of the body of the penis inserting intothe perineal membrane, and further surrounds the dorsal aspect of thecorpus spongiosum 4 surrounding the urethra 5 and the left and rightcorpora cavernosa 6, 7. The ischiocavernosus 1 embraces the crus of thepenis, inserting onto the inferior and medial aspects of the crus and tothe perineal membrane medial to the crus. While the bulbospongiosusmuscle assists the erection by compressing outflow via the deep perinealvein and by pushing blood from the bulb into the body of the penis, theischiocavernosus muscle 1 maintains erection of the penis by compressingoutflow veins and pushing blood from the root of the penis into the bodyof the penis. FIG. 2 is a cross-sectional view through the penis. As canbe seen, the penis is composed of three cylindrical bodies of erectilecavernous tissue: the paired corpora cavernosa 6, 7 dorsally and thesingle corpus spongiosum ventrally. Deep arteries 9, 10 run distallynear the center of the corpora cavernosa, supplying the erectile tissuein these structures. The deep arteries of the penis are the main vesselsof the cavernous spaces in the erectile tissue of the corpora cavernosaand are therefore involved in the erection of the penis. They give offnumerous branches that open directly into the cavernous spaces. When thepenis is flaccid, these arteries are coiled, restricting blood flow.

For reasons of simplification, the following figures only display thecorpora cavernosa 6, 7. FIG. 3 shows a top view on a part of the systemaccording to a first embodiment. More specifically, a single infusionneedle 11 is arranged in a housing 12 with a tip end 13 of the needle 11being positioned such that it can be advanced and retracted through aself-sealing window area 14 in the housing's 12 outer wall 15 in alongitudinal direction 16, so as to pierce the corpus cavernosum 6 or 7located adjacent the window area 14.

Two window areas 14 are provided in the outer wall 15 of the housing 12,one adjacent each of the two corpora cavernosa 6, 7. The infusion needleis displaceable in a lateral direction 17 between the two window areas14 by means of a drive unit D. The same drive unit D or a differentdrive unit may cause the infusion needle 11 to be advanced andretracted. For this purpose, the infusion needle 11 is mounted on aslide 18 for longitudinal advancement and retraction. A conduit 19 isconnected to one end of the infusion needle 11 to supply infusion liquidthrough the infusion needle 11 to the tip end 13 thereof.

In operation, the infusion needle 11 will first be advanced with the tipend 13 thereof to penetrate one of the two self-sealing penetrationwindows 14, injection fluid containing a drug for stimulation of peniserection will be injected into the corpus cavernosum 7 through theinfusion needle 11 and, thereafter, the infusion needle 11 will beretracted again. Upon retraction of the infusion needle, the infusionneedle will be laterally displaced along the direction 17 so that thetip end 13 thereof comes to lie in front of the other of the twoself-sealing window areas 14, the infusion needle 11 will be advancedagain so that infusion liquid can be injected through the tip end 13thereof into the other corpus cavernosum 7 and then the infusion needle11 will be retracted again. At the end of this procedure, the infusionneedle 11 will return to its initial position shown in FIG. 3.

The structure of the system shown in FIG. 3 may be purely mechanical.For instance, as will be described in more detail below, the pressurewith which the infusion liquid is advanced through the conduit 19towards the needle 11 may in cooperation with spring elements cause theneedle 11 to be advanced, retracted and laterally displaced to the otherwindow area 14. Thus, after two pulses of injection fluid advancedthrough the conduit 19 towards the needle 11, the needle 11 willautomatically return to its starting position shown in FIG. 3.

However, it is likewise possible to incorporate a motor M or a pluralityof motors M within the housing 15 in order to achieve the desired needledisplacement by means of the drive unit D. This is schematically shownin FIG. 4. Of course, the motor M will have to be provided with energyand will need to be controlled in an appropriate manner so as to obtainthe desired effect. This is not specifically shown in FIG. 4. The energyis preferably transmitted to the motor M from an energy source eitherremotely implanted inside the patient's body or provided externally ofthe patient's body.

The drive D may be configured such that after each penetration cycle(consisting of two injections) the infusion needle 11 stops at aposition different from the starting position so that the tip end 13thereof penetrates the window areas 14 in the next following injectioncycle at different sites as compared to the foregoing injection cycle.

FIG. 5 shows a top view on a third embodiment which differs from thefirst and second embodiments in that it comprises two infusion needles11 contained in the housing 15. Thus, when infusion liquid is guidedthrough the conduit 19 towards the two infusion needles 11, both needlesare advanced and retracted simultaneously along the direction 16, sothat injection of infusion liquid occurs at exactly the same time. Thedrive unit D or a separate drive unit may be used to turn the turntable20 on which the infusion needles 11 are mounted, stepwise in thedirection 17 so that the window areas 14 will be penetrated by the tipend of the infusion needle 11 at different penetration sites during thenext following injection cycle. Again, one or more motors M, not shownin FIG. 5, may be used for driving one or more of the components of thedrive unit D.

The principle of a guide structure for laterally displacing the infusionneedle will now be described in context with FIG. 6. Such guidestructure may be used e.g. for each of the two infusion needles 11 shownin FIG. 5 or may also be used slightly modified for the lateraldisplacement of the infusion needle 11 shown in FIGS. 3 and 4.

The guide structure 28 is securely fixed adjacent the self-sealingwindow area 14 which itself is implanted adjacent the patient's corpuscavernosum 7. The guide structure 28 comprises a guide pin 27 securelyconnected to the infusion needle 11 (not shown) such that the infusionneedle 11 cooperates with the guide structure 28. Upon advancement orretraction of the infusion needle 11, the guide pin 27 will be guided inthe guide structure 28 and thereby laterally displace the infusionneedle 11, which lateral displacement causes rotation of the turntable20 (not shown in FIG. 6). Resilient flaps 28 a, 28 b within the guidestructure 28 serve to guide the guide pin 27 through the entire guidestructure 28 upon repeated advancement and retraction of the infusionneedle 11. The guide structure 28 is designed to provide differentpenetration sites through the self-sealing window area 14 into thecorpus cavernosum 7. Where it is desired, the trajectory of guidestructure 28 may include a return path 28 c for the guide pin 27 toreturn to its starting position shown in FIG. 6. Such return action willbe caused by a return spring 29 which is permanently fixed to a rigidpart of the housing 15.

The same structure can likewise be used in the embodiments shown inFIGS. 3 and 4 to displace the single infusion needle 11 laterallybetween the two window areas 14. Of course, the structure would have tobe slightly adapted to accommodate for the larger distance to beovercome between the two window areas 14.

FIG. 7 shows a preferred embodiment of a penetration membrane to be usedas the self-sealing window area 14 in the outer wall 15 of the housing12. The penetration membrane 30 is made from a composite material. Thesame material can also be used for other flexible wall portions or foran infusion port that will be described below in connection with anotherembodiment. The composite material of penetration membrane 30 shown inFIG. 7 comprises an outer shape-giving layer 30 a defining a volume inwhich a self-sealing soft material 30 b is contained.

Self-sealing soft material 30 b can be of gel type having a viscositysuch that it does not flow through any penetrations caused by theinfusion needle 11 during penetration of the outer shape-giving layer 30a. Instead of a single outer shape-giving layer 30 a, the shape-givinglayer 30 a may comprise a plurality of layers. The outer shape-givinglayer 30 a preferably comprises silicone and/or polyurethane, since suchmaterials can be produced to have self-sealing properties in respect ofpenetrations resulting from the infusion needle 11.

Instead of a self-sealing membrane, the window area 14 in the outer wall15 of the housing 12 may be formed by one or more flaps, as shown inFIG. 8. Two flaps 30′ being made from a resilient, biocompatiblematerial are arranged so as to form a slit which is normally closed andthrough which the infusion needle 11 can pass when it is advanced. Uponadvancement of the infusion needle 11, the needle will push aside thenormally closed flaps 30′, and when the needle 11 is retracted again,the flaps 30′ will return to their normally closed position so as toform a seal against ingression of body liquid.

FIG. 9 shows a different embodiment. In this case, the self-sealingwindow 14 in the outer wall 15 comprises a door 30″ which can be openedby mechanical action. In the embodiment shown, the door is formed by aflap made from a resilient, biocompatible material which keeps thewindow area 14 closed in its normal position. A pull wire 300 isattached to one end of the door 30″ in order to allow for opening thedoor by pulling the pull wire 300. The pull wire 300 or any other driveconnected to the door 30″ forms part of the drive unit coupled to theinfusion needle 11. For instance, as is shown in FIG. 10, the pull wire300 may be attached directly to the infusion needle 11 so thatadvancement of the infusion needle 11 will simultaneously cause the door30″ to be lifted up so that the infusion needle 11 can pass underneaththe door 30″ and thus penetrate the outer wall 15 easily. Due to theresiliency of the door material, the door 30″ will automatically closewhen the force, such as the pulling force exerted via the pull wire 300,is released. Instead or in addition, the closing action may be supportedby at least one spring element urging the door into its closed position.

FIG. 11 shows a fourth embodiment comprising a plurality of infusionneedles for each of the two window areas 14. In this embodiment it isnot necessary to provide a turntable by which the needles can be pivotedstepwise in order to laterally displace the needles from one penetrationsite to a different penetration site within the same window area 14.Instead, upon successive injection cycles a different one of theplurality of injection needles will be advanced and retracted for eachof the two window areas 14. Thus, the effect achieved is the same as inthe embodiment shown in FIG. 5. However, instead of the turntable 20(FIG. 5) a valve V is needed to direct the infusion liquid to only oneof the plurality of infusion needles 11 in each of the two window areas14. More specifically, depending upon the position of the valve V, afirst one of the infusion needles 11 in the first window area 14 and afirst one of the plurality of the infusion needles 11 in the secondwindow area 14 will be advanced and retracted simultaneously, and duringthe next following infusion cycle, another one of the plurality ofinfusion needles will be advanced and retracted in the two window areas14.

FIG. 12 shows a side view of a fifth embodiment which differs from thefirst and second embodiments shown in FIGS. 3 and 4 in that the singleinfusion needle 11 is not only laterally displaceable in the direction17 between the two window areas 14 but also laterally displaceablebetween different penetration sites 21 within the same penetration area14. More specifically, the direction of lateral displacement of the tipend of the infusion needle 11 within each of said different penetrationareas 14 is perpendicular to the direction of lateral displacementbetween the different penetration areas 14. To achieve this result, thedrive unit D is configured to longitudinally advance and retract theinfusion needle 11 along a direction 16, to pivot the infusion needle 11by means of a turntable 20 between the two penetration areas 14 along apivoting direction 17 and to raise or lower the infusion needle 11 alonga third direction 22 perpendicular to the longitudinal direction 16. Asuitable purely mechanical construction may perform this function.However, one or more motors may also be provided to perform one and/orthe other of these functions.

FIG. 13 shows a side view of a sixth embodiment similar to the fifthembodiment shown in FIG. 12. In contrast to FIG. 12, the infusion needle11 is not only laterally displaceable between different penetrationsites 21 within the same penetration area 14 in a directionperpendicular to the direction of lateral displacement between the twopenetration areas 14, but is also laterally displaceable within the samepenetration area 14 in a direction parallel to the direction of lateraldisplacement between the different penetration areas 14. In other words,the tip end of the infusion needle 11 is laterally displaceable in twodimensions within the same penetration area 14.

FIG. 14 shows a seventh embodiment which enables the infusion needle 11to be moved along a three-dimensional, spherically curved array ofpenetration sites.

In this embodiment, a part of the housing 12, more specifically thewindow area 14, is spherically curved and the needle 11 is mounted in asphere so that upon rotation of the sphere along the directions 17 a and17 b the tip end 13 of the needle 11 can be moved to any position infront of the window area 14. Once an appropriate position has beenadjusted for the tip end 13, the needle 11 can be advanced on the slide18 so as to penetrate the window area 14. Instead of accommodating theslide inside the sphere, it may likewise be mounted on the outer surfaceof the sphere. Similarly, the infusion needle 11 itself can be mountedon the outer surface of the sphere. The mechanism for moving the spherealong the directions 17 a, 17 b can be of many different types, such asmechanical by means of rollers or magnetic.

FIG. 15 shows a side view of an eighth embodiment similar to the thirdembodiment shown in FIG. 5. That is, two needles 11 are provided in acommon housing so as to be longitudinally movable in order to advanceand retract the tip ends thereof through the penetration areas 14. Theinfusion needles 11 is mounted on a turntable 20, as in the thirdembodiment of FIG. 5, so as to change the injection sites 22 within apenetration area 14 upon each injection cycle. In addition, the twoinjection needles can be raised and lowered along a direction 22,similar to the fifth embodiment described above in relation to FIG. 12.Again, the result is that the direction of lateral displacement of thetip ends of the two infusion needles 11 within each of the two differentpenetration areas 14 is perpendicular to the direction of distancebetween the two different penetration areas 14. Of course, thisembodiment, like the sixth embodiment shown in FIG. 13, can also bemodified such that the tip ends of the two infusion needles 11 arelaterally displaceable in two dimensions within the same penetrationarea 14. This is shown in FIG. 16, displaying a side view of a ninthembodiment. In this embodiment, like in the sixth embodiment shown inFIG. 13, the tip ends of the two infusion needles 11 are laterallydisplaceable in two dimensions within the same penetration area 14.

FIG. 17 shows a tenth embodiment with a principle of advancing andretracting the infusion needle 11 by means of a pull wire 101. The pullwire 101 is redirected about a pin 102 such that by pulling the wire 101at an end remotely located somewhere in the patient's body the tip endof the infusion needle 11 will be advanced through the window of thehousing 12. A helical spring provides a counterforce so that theinfusion needle 11 will be retracted once the pulling force on the pullwire 101 is released. This principle can be combined with otherembodiments described hereinbefore and hereinafter. Instead of thehelical spring 104, a second pull wire may be provided to retract theinfusion needle 11. It is even possible to use a single pull wire 101running around two pins 102 in a loop, so that pulling the wire 101 inthe one direction or in the other direction will cause advancement orretraction of the infusion needle 11.

The pull wire 101 and the conduit 19 for the infusion liquid are guidedin a common sheath 103. The common sheath 103 has various functions.First, it gives support to the pull wire 101 in bending sections.Second, it facilitates implantation of the conduit 19 along with thepull wire 101. Third, it protects the pull wire 101 against any build-upof fibrosis. In the case that the infusion needle 11 is long andflexibly bendable, the pull wire 101 and the long infusion needle may beguided in the common sheath 103.

FIG. 18 shows an eleventh embodiment which involves remotely actuatedpull wires 105, 106 guided within a common sheath 103 along with theconduit 19 for the infusion liquid. The pull wires 105 and 106 aredirectly attached to the infusion needle 11 on opposite sides thereof sothat the infusion needle 11 which is mounted on a turntable 20 will belaterally displaced in the one direction or in the other directiondepending on whether the wire 105 or the wire 106 is pulled. Instead ofusing two wires 105, 106, one of the wires may be replaced with apretensioning means, such as the helical spring 104 in FIG. 17. Inaddition, a further wire, in particular third wire (not shown), may beprovided for lateral displacement of the infusion needle 11 in a furtherdirection, so that a two-dimensional lateral displacement can beachieved by pulling the appropriate wires.

The pull wires may alternatively be attached to an element other thanthe infusion needle 11, provided that the infusion needle 11 isconnected to such other element, so that when the other element is movedor turned by pulling one or more of the wires the tip end of theinfusion needle 11 will be displaced accordingly.

In the case that a long, flexibly bendable needle is provided with thetip end thereof being arranged in a first housing for penetrating theouter wall of the first housing and the other end is arranged in aremotely implanted second housing, one can dispense with the turntable20 and achieve accurate lateral displacement of the tip end of theneedle by pulling the appropriate one of three pull wires which areattached either directly or indirectly to the circumference of the frontend of the infusion needle at regularly spaced intervals.

FIG. 19 shows a twelfth embodiment with a different principle ofadvancing and retracting the tip end of the infusion needle, on the onehand, and laterally displacing the tip end of the infusion needle 11, onthe other hand. Instead of pull wires, rotating shafts 107, 108 areprovided. The drive for driving the rotating shafts 107, 108 is remotelylocated somewhere in the patient's body. The front ends of the rotatingshafts have a threading 109, 110, e.g. in the form of a worm screw,meshing with the teeth of a rack 111, 112 formed either directly orindirectly on the infusion needle 11 and on the turntable 20,respectively. Thus, by turning the rotating shaft 107, the infusionneedle 11 will advance or retract, as the case may be, due to thecooperation of the worm screw 109 and the rack 111. The gearing 109, 111may likewise be arranged remote from the first housing, i.e. within thesecond housing accommodating the respective other end of the needle(which is particularly suitable when a long, flexibly bendable needle isused—not shown). Similarly, by turning the rotating shaft 108, theinfusion needle 11 will be displaced laterally in the one or the otherdirection due to the cooperation of the worm screw 110 and the rack 112of the turntable 20. Again, the rotating shafts 107, 108 are guided in acommon sheath 103 along with the conduit 119 for the infusion liquid(or, in the case of a long, flexibly bendable infusion needle, alongwith the long needle—not shown).

In FIGS. 18 and 19, the action of the pull wires 105, 106 and therotating shaft 108 make it possible to laterally displace the tip end ofthe infusion needle 11 between two different penetration areas and/orfrom a first penetration site to a second penetration site within asingle penetration area.

FIG. 20 shows a first variation of an overall system comprising any oneof the first to twelfth embodiment described above. Specifically shownin the variation shown in FIG. 20 is a housing 12 with a single infusionneedle 11 and a drive unit D as described in relation to FIG. 12. Thehousing 12 is implanted with its windows areas 14 positioned adjacentthe corpora cavernosa 6, 7, of which window areas 14 only one is shownin FIG. 20. A motor M is contained in the housing 12 for driving thedrive unit D. While the motor M in the housing 12 may be designed tomove the tip end of the infusion needle 11 in all directions asindicated in FIG. 20, it is particularly preferable in context with along, flexibly bendable infusion needle to cause advancement andretraction of the front end of the long infusion needle by advancing andretracting the entire infusion needle from its rear end using anadditional motor, so as to minimize the motor size in the housing 12 forreasons of space constraints in the injection area. The additional motormay be accommodated in a separate second housing—not shown in FIG.20—along with the rear end of the long infusion needle and possiblyalong with further components remotely implanted in the patient's body.The motor M within the housing 12 (and likewise the afore-mentionedadditional motor) is controlled by means of a control unit C₂constituting the implantable part of a control system which furthercomprises an external data processing device C₁ by which commands andany other kind of data can be sent to the control unit C₂. For instance,the external data processing device C₁ may be used to initiate aninjection cycle from outside the patient's body, this being donewirelessly as indicated by arrow 23. The implanted control unit C₂ notonly controls the motor M inside the housing 12 but also controls theenergy supply from an accumulator A to the motor M inside the housing12.

The external data processing device C₁ may likewise be used to programthe implanted control unit C₂. Also, a data transfer port fortransferring data between the external data processing device C₁ and theimplanted control unit C₂ may be adapted to transfer data in bothdirections.

A feedback sensor F implanted inside the patient's penis is shown hereas being connected to the motor M inside the housing 12 and may likewisebe connected to the implantable control unit C₂. The feedback sensor Fcan sense one or more physical parameters of the patient, such as thedrug level inside the corpora cavernosa, the flow volume through thecorpora cavernosa, the pressure inside the corpora cavernosa and thelike. Other feedback sensors may be provided at a different location soas to sense process parameters of the system, such as electricalparameters, distention, distance and the like.

The conduit 19 connecting the needle 11 with a reservoir comprisingcompartments R₁ and R₂ and the wiring 24 for transmitting electricenergy from the energy source A to the motor M inside the housing 12 areguided through a common conduit 25. Alternatively, where a long andflexibly bendable needle is used, the conduit 19 may guide the longinfusion needle 11 between the reservoir and the housing 12.

In the variation of the entire system shown in FIG. 20, the reservoircomprises a first compartment R₁ with e.g. a saline solution includedtherein, and a second compartment R₂ with e.g. a drug in powder form orfreeze-dried form included therein. A pump P driven by a second motor M₂is arranged to pump infusion liquid from the reservoir R₁ to theinfusion needle 11. The infusion liquid pumped by the pump P will passthrough a mixing chamber 26 into which drugs will be released from thereservoir R₂ in appropriate time coordination. The motor M₂ or adifferent motor may cause the drugs to be released from the secondreservoir R₂. The motor M₂ is also controlled by the control unit C₂.Thus, infusion liquid pumped via the pump P from the relatively largefirst reservoir R₁ through the mixing chamber 26, in which it is mixedwith the drugs released from the second reservoir Rz will reach theinfusion needle 11 which has meanwhile penetrated the self-sealingwindow area 14 of the housing 12 and will flow into the corpuscavernosum 7.

In addition to or instead of the control unit C₂, a pressure sensitiveswitch for activating the motor M inside the housing 12 and/or the motorM₂ may be arranged subcutaneously.

Although the embodiment shown in FIG. 20 may comprise one of a greatvariety of reservoir types, a particular reservoir type will now bedescribed. The volume of the reservoir R₁ is divided into two sectionsby means of a membrane 31. One section is filled with gas whereas theother section is filled with the infusion liquid (saline solution). Aninfusion port 32 allows for refilling the reservoir R₁ with infusionliquid by means of a replenishing needle. When the reservoir R₁ is inits full state, the gas section is at ambient pressure orover-pressurized. As infusion liquid is drawn from the reservoir R₁ bymeans of the pump P upon each infusion cycle, the pressure in the gassection will decrease below ambient pressure, i.e. to a negativerelative value. Depending upon the particular type of pump P, it may beadvantageous to provide a single acting ball valve to prevent anybackflow from the pump P to the reservoir R₁.

There are various ways of providing the motors M and M₂ with energy. Inthe variation shown in FIG. 20, energy is supplied from outside thepatient's body either for direct use by the motors and/or for chargingthe accumulator A, which may be in the form of a rechargeable batteryand/or a capacitor. An extracorporal primary energy source E transmitsenergy of a first form through the patient's skin 100 to an energytransforming device T which transforms the energy of the first form intoenergy of a second form, such as electric energy. The electric energy isused to recharge the accumulator A which provides secondary energy tothe motor M upon demand.

The external primary energy source E may be adapted to create anexternal field, such as an electromagnetic field, magnetic field orelectrical field, or create a wave signal, such as an electromagneticwave or sound wave signal. For instance, the energy transforming deviceT as shown in FIG. 20 may act as a solar cell, but adapted to theparticular type of wave signal of the primary energy source E. Theenergy transforming device T may also be adapted to transformtemperature changes into electrical energy.

Instead of the external primary energy source E, an implantable primaryenergy source E may be used, such as a regular long-life battery insteadof the accumulator A.

The energy signal may also be used to transmit signals from the externaldata processing device C₁ by appropriate modulation of the energysignal, regardless of whether the energy is transmitted wirelessly or bywire, the energy signal thereby serving as a carrier wave signal for thedigital or analog control signal. More particularly, the control signalmay be a frequency, phase and/or amplitude modulated signal.

FIG. 21 shows a second variation of the entire system which basicallydiffers from the system of FIG. 20 only in that the motor M inside thehousing 12 is dispensed with. Instead, the motor M₂ is used to drive thedrive unit D. This is achieved by means of a rotating shaft 33 in theform of an elastically bendable worm screw, the rotating shaft 30replacing the wiring 24 of the system shown in FIG. 20. Alternatively,where the infusion needle 11 is long and flexible, the infusion needlemay be advanced by engagement of two helical gears, one of which beingformed on the rear end of the infusion needle, or by a similar gearingcooperating with the infusion needle's rear end.

FIG. 22 shows a third variation of the entire system which operatespurely mechanically. The reservoir R₁ containing the infusion liquid,i.e. the saline solution, is of balloon type, thereby functioning bothas a reservoir and as a pump if it is compressed manually from outsidethe patient's body. The pressure generated in the reservoir R₁ will acton the reservoir R₂ containing the drug. Upon a certain pressure, thedrug will be released from the reservoir R₂ into the mixing chamber 26and upon further increase of the pressure the infusion liquid will beallowed to enter the mixing chamber 26, mix with the drug released fromthe reservoir R₂, flow towards the infusion needle 11, and build uppressure on the infusion needle 11 such that the drive unit D is causedto advance the infusion needle 11 through the self-sealing window area14 into the patient's corpus cavernosum. Once the pressure is released,the infusion needle 11 will retract automatically due to mechanicalspring forces or the like and move into a different position in which itcan penetrate the second of the two self-sealing window areas 14 whenthe reservoir R₁ is compressed again. Where two infusion needles 11 areprovided, a single compressing action on the reservoir R₁ would besufficient to inject the drug into both the left and right corporacavernosa.

FIG. 23 shows a first principle of how drugs within a plurality ofcompartments 34 of the reservoir R₂ can be released one at a time by apurely hydromechanical solution. As the infusion liquid is urged fromthe reservoir R₁ towards the conduit 19 leading to the infusion needleor needles, it is first blocked by a spring-loaded ball valve 34 whichopens only when a certain pressure is exceeded. The pressure building upin front of the ball valve 34 is guided by means of a stepper valve Vsequentially onto one of a plurality of compartments 35. Thecompartments are each formed as a cavity 35 within a piston 36. Once acertain pressure is exceeded, the piston 36 will be pushed into aposition where the compartment 35 is in flow communication with a mixingchamber 26. In the state shown in FIG. 23, three pistons 36 have alreadybeen pushed into such position. When the pressure in the reservoir R₁ isfurther increased, the spring force of the ball valve 34 will beovercome and the infusion liquid urged from the reservoir R₁ towards theconduit 19 will take with it the drug that has been released into themixing chamber 26.

FIGS. 24 to 26 show a second principle of realizing the reservoir R₂comprising a plurality of small drug compartments 35, 35 a, 35 b. Thedrug compartments are integrally formed in a tape 201 which is wound ona first reel 202 and can be unwound from said first reel 202 onto asecond reel 203. The reels 202, 203 and the tape 201 are contained in acassette 200 which may be inserted in the entire system so as to formpart of the reservoir. The cassette 200 is preferably replaceable.

As can be seen in FIG. 25, the compartments 35, 35 a, 35 b containingthe drug e.g. in powder form or freeze-dried form are arranged in aplurality of rows as seen in the transporting direction (indicated bythe arrow). However, the compartments 35 of one row are a certaindistance offset in the transporting direction from the compartments 35 aand 35 b of the other rows. Thus, when the tape 201 is wound from reel202 to reel 203, it is guided through a conduit 204 forming part of thecassette 200 through which the infusion liquid is pumped from thereservoir R₁ to the infusion needle or needles, and the compartments 35,35 a, 35 b will enter the conduit 204 one after the other.

While it is conceivable to open one of the compartments 35, 35 a, 35 bthat has entered the conduit 204 by mechanical action, such as a hammeror piercing element, the opening of the compartments 35 in theembodiment shown in FIGS. 24 to 26 needs no further action other thanwinding the tape 201 onto the reel 203. That is, as can be seen fromFIG. 26, when the tape 201 enters the conduit 204 through a first slit205, the compartments 35 will not be damaged due to the fact that theslit 205 is relatively wide and is closed by two soft sealing lips 206.However, when the tape 201 exits the conduit 204 on the other sidethereof, it will have to pass a narrower second slit 207 with frontedges 208 that are not resilient. The compartments 35 will thereforeburst on their way out of the conduit 204 when they slip between theedges 208 of the narrow slit 207. Soft seals 209 in the slit 207 preventliquid from leaking from the conduit 204.

The entry 210 and the exit 211 of the conduit 204 within the cassette200 each include a valve that automatically closes when the cassette 200is removed from the system and automatically opens when the cassette 200is installed in the system. This allows for replacement of the cassette200 without adversely affecting the remaining components of the overallsystem.

FIGS. 27 and 28 show a third principle of realizing the reservoir R₂comprising a plurality of small drug compartments 35. While FIG. 27shows a cross-sectional plan view according to section BB in FIG. 28,FIG. 28 shows a cross-sectional side view thereof according to sectionAA in FIG. 27. The compartments 35 containing the drug in powder form orfreeze-dried form are arranged in a rotatable plate 37. A motor M₂ isprovided to rotate the plate 37 about an axis 38.

The motor M₂ is controlled to advance the plate 37 stepwise so as tobring one compartment 35 at a time in line with the conduit 39connecting the reservoir R₁ containing the saline solution with theinfusion needle or needles. Energy is supplied to the motor M₂ from theaccumulator A via the control unit C₁.

The rotatable plate 37 is mounted in a fixed base plate 39 which itselfis fixedly mounted in a housing 40 insulating the base plate 39 and therotatable plate 37 thermally against an outer housing 42. A coolingdevice 41 is provided to cool a liquid surrounding the base plate 39 androtatable plate 37 down to a temperature below 37° C. This serves toprotect the drugs inside the compartment 36 from degrading too quickly.The accumulator A supplies the cooling device 41 with energy.

FIG. 29 shows a general principle of cooling the reservoir R₂ containingthe drug to be cooled. The cooling device 41 may be an electrothermalcooler, i.e. based on the Peltier effect consuming electric energy, ormay be of the refrigerator type. Accordingly, the cold part of thecooler 411 s placed on the side to be cooled whereas the warm part ofthe cooling device 41 is placed on the other side so that the heatenergy can be dissipated to the outside. An increased surface 41 a onthe warm side of the cooling device 41 serves to increase heatdissipation. Furthermore, a heat exchanging fluid may be passed througha conduit 41 b along the increased surface 41 a to transfer thedissipated heat energy to a remote location within the patient's bodywhere the heat is dissipated into the patient's body through a specificheat exchanging surface 41 c.

FIG. 30 shows a different principle of cooling the drugs contained inthe reservoir R₂. In this embodiment, two chemicals X1 and X2 arecontained separate from each other in respective compartments of thecooling device 41. When the chemicals X1 and X2 are brought together,they will react with each other and such reaction will consume energywhich is absorbed as thermal energy from the surroundings. By means oftwo pistons 41 d, 41 e, the chemicals X1, X2 are dispensed into acooling line 41 f in a controlled manner, which cooling line ispreferably in contact with the housing 40 containing the reservoir R₂.The chemical mixture X1-X2 displaced within the cooling line 41 f willflow back into the chamber containing the chemicals X1, X2, but onto theother side of the pistons 41 d, 41 e.

A further embodiment is shown in FIG. 31. In this embodiment, again, twoseparate needles are provided, one infusion needle for each of the leftand right corpora cavernosa. However, unlike the previously discussedembodiments, the two needles each have their own housing 12 implanted inthe patient's body with their respective self-sealing window area 14adjacent the left and right corpora cavernosa, respectively. Thisprinciple is shown in FIG. 32 in more detail with respect to one of thetwo needles. The drive unit D comprises a piston 50, to which the hollowinfusion needle 11 is attached. The piston 50 separates a first chamber51 a in front of the piston 50 and a second chamber 51 b behind thepiston 50. While the pressure in the first chamber 51 a corresponds tothe pressure exerted by the pump P, the pressure in the second chamber51 b can be kept at a lower value. The second chamber 51 b may be filledwith a liquid, such as the infusion liquid, and the liquid may be urgedinto a flexible volume 52. The flexible volume 52 could be of simpleballoon type so as to fill up without exerting any strong counterforce.

Instead of the flexible volume 52, a conduit 53 may connect the secondchamber 51 b with the reservoir R₁. Thus, when the needle 11 isadvanced, liquid will be dispelled from the second chamber 51 b throughthe conduit 53 into the reservoir R₁, and as the needle 11 is retractedby means of a return spring 55, liquid will be drawn from the reservoirR₁ through the conduit 53 back into the second chamber 51 b.

The injection process is carried out as follows. As the pressure isincreased in the first chamber 51 a by means of the pump P, the needle11 will be displaced against the force of the spring 55 of the driveunit B. Thus, the tip end 13 of the infusion needle 11 will penetratethrough the self-sealing window area 14 press-fitted into the wall 15 ofthe housing 12 and will further penetrate any fibrosis having built upin front of the housing. When the return spring 55 is completelycompressed and the pressure built up by the pump P is further increased,a ball valve 56 will be displaced against a second return spring 57which is stronger than the first return spring 55. That way, as long asthe pressure is held at a sufficiently high level, infusion liquid willbe pumped from the reservoir R₁ through the conduit 19, the hollowinfusion needle 11 and the needle's laterally arranged exit port intothe patient's body. Upon pressure release, the ball valve 56 will closedue to the return springs 55 and 57, and then the needle 11 will beretracted to its initial position shown in FIG. 23.

FIG. 33 shows the same principle, however, employing long, flexiblybendable infusion needle with only their respective front endsaccommodated in the housing 12. As the pressure is increased in thefirst chamber 51 a by means of the pump P remote from the housing 12accommodating the tip end 13 of the infusion needle 11, the entireinfusion needle 11 which is guided in the conduit 19 will be displacedagainst the force of the spring 55 of the drive unit B.

It may be advantageous not to pierce any living tissue by means of theinjection needle 11 once it is advanced through the outer wall 15 of thehousing 12. Therefore, as shown in FIG. 34, a tube 58 may be placed infront of the window area 14. The cross-sectional form of the tube 58 maybe adapted to the cross-sectional form of the window area 14, i.e. wherethe window area 14 is rectangular, the tube 58 likewise has arectangular cross-section.

The exit end of the tube 58 has an open area 59 sufficiently large toprevent growth of fibrosis from spanning over the open area. Fibrosiswill slowly grow into the tube along the tube's inner surface, before itreaches the window area 14 after a relatively long time. The tip end 13of the needle 11 will therefore not have to penetrate any fibrosisduring the first while after implantation of the system. Preferably, theopen area 59 has an opening width of at least 3 mm. The length of thetube 58 may be in the range of 4 mm to 30 mm. The opening width 59 andthe length of the tube 58 should be adjusted such that the substanceinjected into the tube 58 can safely seep into the patient's body. Thus,the longer the tube is, the larger the opening width thereof should be.

FIGS. 35A and 35B show a first embodiment for displacing the tip end ofthe infusion needle 11 in two or more different directions, i.e. atwo-dimensional displacement. More specifically, FIG. 35A shows a planview, whereas FIG. 35B shows a side elevational view schematically. Ascan be seen, a plate 60 to which the infusion needle 11 is fixedlymounted has a projection 61 extending into a frame 62 within which theprojection 61 is free to move in any direction. Electromagnetic coils 63are mounted on the sides of the frame 62 and are individuallyenergizable. The electromagnetic coils 63 constitute the first part ofan electromagnetic drive whereas the projection 61 is configured toconstitute the second part of the electromagnetic drive. Thus, when oneor more of the electromagnetic coils are energized, an electromagneticfield is created in the frame 62 and the electromagnet second part, i.e.the projection 61, will adjust its position within such fieldaccordingly. Due to the fact that the infusion needle 11 is fixedlymounted to the plate 60, the infusion needle 11 will move along with theprojection 61. This way, the infusion needle 11 can be advanced andretracted and can also be displaced laterally.

Of course, the infusion needle 11 may be attached to the electromagneticdrive in a different manner, e.g. perpendicular to the plane defined bythe electromagnetic coils 63 (rather than in parallel as in FIG. 35B).As a result, the infusion needle would be laterally displaceable in aplurality of directions (rather than being advanceable and retractable).

Alternatively, the electromagnetic drive may be such as to displace theinfusion needle in any lateral direction and, in addition, to advanceand retract the infusion needle. This can be achieved e.g. with astructure as schematically shown in FIG. 35C relating to a secondembodiment for displacing the tip end of the infusion needle 11. FIG.35C shows an elevational side view similar to FIG. 35B, but theelectromagnetic coils 63 do not define a single plane, but rather aplurality of planes is defined one above the other by providingadditional electromagnetic coils 63 in a vertical direction. The topplan view would be similar to FIG. 35A. This way, the electromagnetsecond part 61 fixedly connected to the needle 11 moves within athree-dimensional frame 62 depending on the energization of respectiveones of the magnetic coils 63.

FIGS. 36A and 36B show a plan view and a side view of a third embodimentof an electromagnetic drive for moving the infusion needle 11 in aplurality of directions. In this embodiment, the electromagnetic coils63 constituting the electromagnet first parts are arranged in a firstplane and the electromagnet second part constituted by the protrusion 61fixedly connected to the infusion needle 11 via the plate 60 is movablein a plane in front of or behind the plane defined by the electromagnetfirst parts. However, the electromagnetic coils 63 are orienteddifferently in this third embodiment. Again, depending upon theenergization of the individual electromagnetic coils, the electromagnetsecond part, i.e. the protrusion 61, will adjust its position in thecreated electromagnetic field within the frame 62.

FIG. 37 shows an overall system of the invention implanted in apatient's body according to a fourth variation. This variation differsfrom the first to third variations described in relation to FIGS. 21 to23 in that the infusion needle is not accommodated in a housing so as tobe laterally displaceable. The infusion needle 11 is instead guided in acatheter 19 ending inside the patient's corpus cavernosum. Accordingly,two separate needles 11 are provided, which are long and flexiblybendable. They are advanced from the rear ends thereof so as topenetrate a window area 14 at the front end of the catheter, whenever adrug is injected to achieve an erection. While the variation shown inFIG. 37 is purely mechanic, similar to the variation shown in FIG. 23,the overall system may be more complex, e.g. similar to the variationsdescribed in relation to FIGS. 21 and 22.

FIG. 38 shows an overall system of the invention according to a fifthvariation which is similar to the afore-mentioned fourth variation,except that there is no needle provided in the catheter 19. Thesubstances from the reservoirs R₁ and R₂ are delivered to the corpuscavernosum through the catheter 19. Accordingly, the catheter 19 has anopen end or, more preferably, an end that can be opened when needed,e.g. mechanically as described above.

FIG. 39 shows an overall system of the invention according to a sixthvariation which is similar to the afore-mentioned fifth variation,except that the catheter does not end in the corpus cavernosum, but endsin close proximity thereto, such as in muscle tissue regulating bloodflow through the patient's left and right corpus cavernosum and/or inanother kind of tissue in close proximity to the patient's left andright corpus cavernosum. Alternatively, the catheter 19 may guide aninfusion needle, such as the infusion needle 11 as described in thefourth variation in relation to FIG. 37. Thus, when the catheter 19 isimplanted, the drugs are delivered through the catheter 19 or throughthe infusion needle 11, as the case may be, outside the corporacavernosa.

It should be appreciated that the features of all the above describedvariations and embodiments may be combined and/or inter-exchangeddeliberately, unless this is technically impossible.

A method of treating a human being (or an animal) by implanting at leastpart of the system in the patient's body comprises the steps of cuttingthe skin, dissecting free an area near the left and right corpuscavernosum, placing the fully implantable drug delivery device withinsaid dissected area with the a least one catheter arranged next to theleft and right corpus cavernosum and/or the two deep arteries of theright and left corpus cavernosum and/or muscle tissue regulating bloodflow through the patient's left and right corpus cavernosum and/oranother kind of tissue in close proximity to the patient's left andright corpus cavernosum, so as to allow for stimulation of peniserection by delivering a drug through said at least one catheter, andclosing at least the skin after implantation of at least parts of thesystem.

A method of treating a human being (or an animal) may likewise comprisethe steps of cutting the skin, dissecting free the left and right corpuscavernosum, placing the drug delivery device within said dissected areawith the a least one catheter ending in the left and right corpuscavernosum and/or the two deep arteries of the right and left corpuscavernosum and/or muscle tissue regulating blood flow through thepatient's left and right corpus cavernosum and/or another kind of tissuein close proximity to the patient's left and right corpus cavernosum, soas to allow for stimulation of penis erection by delivering a drugthrough said at least one catheter, and closing at least the skin afterimplantation of at least parts of the system.

The method of treating a human being (or an animal) may particularlycomprise the steps of cutting the skin, dissecting free a first areanear the left and right corpus cavernosum, placing the at least onehousing accommodating the at least one infusion needle within saiddissected area such that the tip end of the at least one infusion needlecan penetrate, when penetrating the housing's outer wall, into at leastone of the left and right corpus cavernosum and/or at least one of thetwo deep arteries of the right and left corpus cavernosum and/or intomuscle tissue regulating blood flow to the patient's left and rightcorpus cavernosum and/or into another kind of tissue in close proximityto the patient's left and right corpus cavernosum allowing stimulationof erection of the two corpora cavernosa, and finally closing at leastthe skin after implantation of at least parts of the system.

Where parts of the system are implanted remote from the corporacavernosa, a second area remote from the first area may be dissectedfree in order to place e.g. the at least one reservoir in the patient'sbody at the remote second area, with a conduit connecting the reservoirwith the at least one infusion needle accommodated in the at least onehousing. In this case, it is preferable to place the reservoir adjacentthe patient's symphyseal bone.

One or more of the following elements may be placed within the patient'sbody remote from the housing or housings accommodating the at least oneneedle:

-   -   at least part of the drive unit D,    -   the reservoir R₁, R₂,    -   the pump P,    -   at least one motor M, M₂ for actuation of the drive unit D or a        drive driving the drive unit, and/or the pump P or any other        energy consuming part of the system,    -   energy storage means A for providing the at least one motor with        energy,    -   galvanic coupling elements between either an external energy        source E or the energy storage means A and the motor M, M₂ for        transmitting energy to the motor in contacting fashion,    -   wireless coupling elements adapted to connect either the motor        M, M₂ or the energy storage means A or both to an extracorporal        primary energy source for transmitting energy to either the        motor or the energy storage means or both in non-contacting        fashion,    -   control unit C1 for controlling the motor M, M₂,    -   a data transmission interface for wirelessly transmitting data        from an external data processing device C₂ to the control unit        C₁,    -   the feedback sensor F,    -   wireless energy transforming means, and    -   the injection port 32 for refilling the reservoir R₁.

The invention claimed is:
 1. A penis erection stimulation system,comprising a fully implantable drug delivery device adapted to deliver adrug in relation to a penis to achieve erection of the penis, whereinthe drug delivery device comprises at least one infusion needle adaptedto be placed outside a left or a right corpus cavemosum in closeproximity thereto, wherein the fully implantable drug delivery device isadapted to be noninvasively powered, when implanted, wherein theinfusion needle is adapted to be advanced into and retracted from atleast one of; the left or right corpus cavemosum, one or two of deepartries thereof, muscle tissue regulating blood flow through the right,left or both corpus cavemosum and tissue in close proximity to the left,right or both corpus cavernosum, and whenever the needle is advanced,when the drug delivery device is implanted, the drug delivery device isfurther adapted to deliver drugs through the infusion needle into atleast one of; the left or right corpus cavemosum, one or two of the deeparteries thereof, muscle tissue regulating blood flow through the right,left or both corpus cavernosum and tissue in close proximity to theleft, right or both corpus cavemosum, and wherein the at least oneinfusion needle being placed in a body configured to fit in a positionin between the left and right corpus cavernosum at a base of the peniletissue placed inside a human body where the left and right corpuscavernosum are deviating away from each other.
 2. The system of claim 1,wherein the at least one infusion needle has a tube-like body closed atthe tip end and having a laterally arranged delivery exit port.
 3. Thesystem of claim 1, wherein the at least one infusion needle is disposedat least partly within at least one housing with a tip end of the atleast one infusion needle arranged for penetrating the at least onehousing's outer wall, the at least one housing being adapted forimplantation inside a patient's body, and wherein at least one driveunit (D) adapted for implantation inside the patient's body is provided,the at least one drive unit being coupled to the at least one infusionneedle and arranged at least for advancing and retracting the tip end ofthe at least one infusion needle so that the at least one infusionneedle penetrates, upon advancement of the tip end or ends thereof, saidouter wall in at least one penetration area so as to allow forstimulation of penis erection by injecting the substance through said atleast one penetration area via the at least one infusion needle.
 4. Thesystem of claim 1, wherein the drive unit is configured to laterallydisplace the tip end of at least one of said at least one infusionneedle in at least two different lateral directions to differentpenetration sites within said at least one penetration area.
 5. Thesystem of claim 3, wherein the at least one infusion needle is arrangedfor penetrating the at least one housing's outer wall in at least twodifferent penetration areas.
 6. The system of claim 5, wherein thesystem is adapted such that the at least one infusion needle penetratessaid at least two different penetration areas upon a single command orsingle action from the patient.
 7. The system of claim 6, wherein the atleast one drive unit is adapted for advancing and retracting the tip endof the at least one infusion needle in such way that it penetrates, uponadvancement of the tip end or ends thereof, said at least two differentpenetration areas either simultaneously or in immediate time succession.8. The system of claim 3, wherein at least in the penetration area orareas the outer wall is made from a material which is self-sealing inrespect of penetrations resulting from said at least one infusionneedle.
 9. The system of claim 8, wherein the self-sealing materialcomprises a penetration membrane integrated in the outer wall by beingsealingly press-fitted into the outer wall.
 10. The system of claim 1,wherein the at least one infusion needle is flexibly bendable, whereinthe tip end of each of the at least one infusion needle is arranged forpenetrating the outer wall of a first housing and the other end thereofis arranged in a second housing for remote implantation inside thepatient's body, the injection needle being sufficiently long to bridgethe distance from the second housing for remote implantation to thefirst housing and further through the first housing up to the outer wallof the first housing.
 11. The system of claim 1, further comprising atleast one reservoir (R₁, R₂) adapted for implantation inside thepatient's body to store the drug to be delivered, wherein the reservoircomprises at least one first compartment accommodating or adapted toaccommodate a first substance and at least one second compartmentaccommodating or adapted to accommodate a second substance, furthercomprising a mixing chamber for mixing the substance from the at leastone first compartment, wherein the substance contained in the at leastone second compartment is in at least one of: powder form, freeze-driedform.
 12. The system of claim 11, wherein a plurality of the secondcompartments is liquid-tightly sealed against the at least one firstcompartment, wherein the system further comprises a mechanism forindividually opening a connection between the second compartments andthe at least one first compartment.
 13. The system of claim 3, furthercomprising at least one of; at least one pump adapted for implantationinside the patient's body to advance the drug from the reservoir to theat least one drug delivery device, and an actuating means are providedfor direct manual operation of the pump and/or the drive unit.
 14. Thesystem of claim 13, wherein at least one motor is provided for actuatingthe at least one of the pump (P), the drive unit and any otherimplantable energy consuming part of the system.
 15. The system of claim14, further comprising an energy source for providing energy to at leastone of the pump, the drive unit, the motor and any other energyconsuming part of the system, and wherein the system futher comprisescoupling elements for wireless energy transfer from the external powersupply to the energy storage means for charging the energy storage meansfrom outside a patient's body, when the energy storage means isimplanted in a patient's body, wherein at least one feedback sensor isprovided and adapted to sense one or more physical parameters of thepatient and/or process parameters of the system, further comprising afeedback subsystem adapted to wirelessly send feedback informationrelating to the energy to be stored in the energy storage means frominside the human body to the outside thereof, wherein the system isadapted to use the feedback information for adjusting the amount ofwireless energy transmitted by the energy transmitter and/or adapted toprovide feedback on parameters relevant for the treatment, including theone or more physical parameters of the patient and/or the processparameters of the system.
 16. The system of claim 1, wherein at leastone feedback sensor (F) is provided and adapted to sense one or morephysical parameters of the patient and/or process parameters of thesystem, wherein the at least one feedback sensor is adapted to sense oneor more parameters of a group of parameters relating to: drug level,flow volume in a blood vessel, pressure, electrical parameters,distension, distance, and a parameter related to the charging processfrom inside the patient's body to the external power supply forcontrolling the charging process, further comprising a feedbacksubsystem adapted to wirelessly send feedback information relating tothe energy to be stored in the energy storage means from inside thehuman body to the outside thereof, wherein the system is adapted to usethe feedback information for adjusting the amount of wireless energytransmitted by the energy transmitter and/or adapted to provide feedbackon parameters relevant for the treatment, including the one or morephysical parameters of the patient and/or the process parameters of thesystem.
 17. The system of claim 1, further comprising an energy sourcefor providing energy to at least one of; a pump, a drive unit, a motorand any other energy consuming part of the system, wherein the energysource comprises at least one of; an internal power supply forimplantation within the housing implanted in a patient's body, aninternal power supply for implantation remote from the housingaccommodating the infusion needle implanted in a patient's body, anexternal power supply adapted to wirelessly transfer energy, and anexternal power supply for charging the internal power supply fromoutside the patient's body, when the internal power supply is implantedin a patient's body.
 18. The system of claim 1, wherein at least onecontrol unit is provided for controlling at least one of, an amount ofthe drug to be delivered into the patient's body a pump, a drive unit, amotor, and any other energy consuming part of the system, wherein thecontrol unit comprises at least one of; an external component forcontrolling the system from outside the patient's body, an implantablecontrol unit adapted to receive a signal from the external control unit,and a pressure sensitive switch so as to be manually operable by thepatient when the switch is implanted subcutaneously in a patient's body.